The social infrastructures relating to means for transmitting information have advanced. This has made it possible to acquire, process, and send out many pieces and various kinds of information with the use of a data processing device not only at home or office but also at other visiting places.
With this being the situation, portable data processing devices are under active development.
For example, a flexible active matrix light-emitting device in which an organic EL element or a transistor serving as a switching element is provided over a film substrate is disclosed as an example of a portable data processing device (see Patent Document 1).